A continuum model for decoherence in 1D transport

Şenozan, Selma
In this thesis we study the conductance of a one dimensional conductor in the presence of dephasing. Dephasing effects are modelled after generalizing Büttiker̕s dephasing model (Phys. Rev. B 33, 3020 (1986)) to a continuous one. Infinitely many electron reservoirs are coupled to the conductor as phase breakers and the method for calculating the conductance is presented. We investigate how this continuum decoherence effect the conductance of a wire, with single and double rectangular barriers.


A physical model for dimensional reduction and its effects on the observable parameters of the universe
Karaca, Koray; Bayın, Selçuk; Department of Physics (2005)
In this thesis, assuming that higher spatial dimensions existed only during the inflationary prematter phases of the universe, we construct a (1+D)-dimensional (D>3), nonsingular, homogeneous and isotropic Friedmann model for dimensional reduction. In this model, dimensional reduction occurs in the form of a phase transition that follows from a purely thermodynamical consideration that the universe heats up during the inflationary prematter phases. When the temperature reaches its Planck value Tpl,D, which ...
Development of software for calculations of the reflectance, transmittance and absorptance of multilayered thin films
Şimşek, Yusuf; Esendemir, Akif; Department of Physics (2008)
The aim of this study is to develop a software which calculates reflection, transmission and absorption of multilayered thin films by using complex indices of refraction, as a function of both wavelength and thickness. For these calculations matrix methods will be considered and this software is programmed with the matrix method. Outputs of the program will be compared with the theoretical and experimental results studied in the scientific papers.
3+1 orthogonal and conformal decomposition of the einstein equation and the adm formalism for general relativity
Dengiz, Suat; Tekin, Bayram; Department of Physics (2011)
In this work, two particular orthogonal and conformal decompositions of the 3+1 dimensional Einstein equation and Arnowitt-Deser-Misner (ADM) formalism for general relativity are obtained. In order to do these, the 3+1 foliation of the four-dimensional spacetime, the fundamental conformal transformations and the Hamiltonian form of general relativity that leads to the ADM formalism, defined for the conserved quantities of the hypersurfaces of the globally-hyperbolic asymptotically flat spacetimes, are recons...
İnvestigating the semileptonic B to K1(1270,1400) decays in QCD sum rules
Dağ, Hüseyin; Zeyrek, Mehmet Tevfik; Department of Physics (2010)
Quantum Chromodynamics(QCD) is part of the Standard Model(SM) that describes the interaction of fundamental particles. In QCD, due to the fact that strong coupling constant is large at low energies, perturbative approaches do not work. For this reason, non-perturbative approaches have to be used for studying the properties of hadrons. Among several non-perturbative approaches, QCD sum rules is one of the reliable methods which is applied to understand the properties of hadrons and their interactions.\ In th...
Density functional investigation of nano-structures
Üzengi Aktürk, Olcay; Tomak, Mehmet; Department of Physics (2010)
In this thesis, we first investigate the physical properties of some metal atoms, molecules and their clusters. We then study the interaction of these with silicon and graphene surfaces. The adsorption of NH3 and H2S molecules on Au3Pt3 is also studied. We calculate the equilibrium atomic structures of metal clusters using density functional theory (DFT) up to eight atoms. The electronic structures of these free and adsorbed clusters are also calculated in detail. We find that the adsorption generally modif...
Citation Formats
S. Şenozan, “A continuum model for decoherence in 1D transport,” M.S. - Master of Science, Middle East Technical University, 2005.